Equine tick surveillance

A research project conducted by the Western College of Veterinary Medicine, University of Saskatchewan

A WCVM research team is investigating the prevalence and risk of exposure to the tick-borne diseases, equine granulocytic anaplasmosis (A. phagocytophilum
infection) and Lyme disease (Borrelia
burgdorferi infection), in horses.

As part of their studies, the WCVM researchers are aiming to better understand tick populations relevant to horses in Saskatchewan and are asking veterinarians and horse owners to submit any ticks found on horses within the province. Researchers are accepting ticks of any life stage (including larval, nymph and adult stages) and are actively seeking tick submissions throughout 2013.

Tick submissions: collection containers

You can submit ticks — alive or dead — in a sealed container. To ensure that ticks are not damaged
during shipment, please place specimens in
a suitable collection container made out of rigid plastic such as a pill bottle or a film canister. To avoid accidents, please do not use glass containers to submit ticks.

Please place moistened tissue paper, paper towels, gauze or cotton in the collection container to
protect the specimen during shipment and to maintain any ticks that are alive during
transport. The moistened material also ensures that the ticks (dead or alive) do not dry out and break during shipping.

Tick submissions: collection details

When submitting ticks, please include as
much of the following information as possible:

The horse owner’s name and
contact information. Please note: This information is for follow up only and will be kept confidential.

The locality from where the
tick(s) were collected.

The date the tick(s) were
collected.

The horse's travel history, specifically within the two weeks prior to finding the tick(s).

Please use one container per horse and one submission form per horse. For example, if you submit ticks collected from three of your horses, please submit three containers and three submission forms. Please include the name of the horse (or other ID matching that on the submission form) on each container.

Q. Why is the WCVM research project targeting these specific tick-borne diseases?

Equine granulocytic anaplasmosisand Lyme
disease are tick-borne diseases that have historically been considered exotic to
Canada. However, in recent years, several
dogs and a single horse have been diagnosed with the disease in Saskatchewan.

Both organisms are carried by the
black-legged tick (Ixodes scapularis). Although there is no known endemic
population of black-legged ticks in Saskatchewan, these ticks have been
transported into the province by migratory birds. In addition, evidence for local and distant migration
of the tick and simulation models of climate changes are suggesting that the
geographic range for established tick populations is expanding towards the
North and West.

Q. What's the goal of the WCVM research study?

The goal is to answer some fundamental questions relating to tick
ecology and their relative importance in disease transmission. We are looking
for ticks collected from horses in all parts of the province and at all times
of the year. We expect that most ticks will be found in the spring and early
summer. However, as Ixodes scapularis is mostly active in the fall, we
also hope to obtain specimens later this year.

Since February 2012, more than 550 ticks have been submitted for the
study; most of the submissions have been from the Saskatoon area with others
coming from the southeastern and southwestern parts of the province.

The
ticks comprised a variety of species which included:

Dermacentor albipictus (the winter or moose tick)

Dermacentor andersoni (the Rocky
Mountain wood tick)

Dermacentor variabilis
(the American dog tick).

As these ticks do not transmit the diseases we are
interested in studying, the ticks were identified but not tested for presence
of infectious organisms.

Identification of ticks (and testing of relevant ticks
for their disease carrier status) is done in collaboration with Dr. Neil
Chilton of the University of Saskatchewan's Department of Biology. Please note
that veterinarians and horse owners who submit ticks will be informed of their
identification results.

We wish to thank all veterinarians and horse owners who have been and
are still submitting ticks for the study!

Q. What other research results have
you obtained to date?

We have tested more than 400 blood samples from horses in Saskatchewan
and other provinces for antibodies against Anaplasma
phagocytophilum and Borrelia
burgdorferi.

Interestingly, although few horses overall had measurable
antibody titres, we found horses that tested positive in provinces with as well
as those without known established Ixodes
populations. We cannot be sure whether these horses encountered the organisms
in Canada, and we are doing a follow-up survey to compare travel history and
management factors between horses that did or did not have measurable antibody
titres.

Questions

If you have any questions relating to this
tick surveillance survey, or if you have a case in which you suspect one of these
tick-borne diseases, please contact Dr. Gili Schvartz (306-966-7095) or Dr. Katharina Lohmann (306-966-7157).